I know it is a Ubuntu PPA, but under the circumstance it's my best bet to use Gimp-Painter (a modified version of Gimp). I can't for the life of me compile it (2.6.11) but 2.7.2 git Gimp compiles just fine. So I've decided to have it installed as long as it doesn't hinder any other part of my system (I uninstall it every time I install something with apt-get)